Fix Char comparisons

Fixes evancz/Elm#392
Add efficient update function for Dict
Add note about how to interpret JS functions
Get rid of check on how many exposed modules. That's for validation elsewhere
Implement more general Dict update.
Merge pull request #393 from maxsnew/dict

Add efficient update function for Dict
Fix issue #397. Core issue was that scanning for infix declarations was not clever about strings.
Merge branch 'dev' of https://github.com/evancz/Elm into dev
Go to original error style. I think it's nicer.
Add note about no sharing between top-level and let-bound type variables
Use instanceof for performance
Further optimizations
Merge pull request #399 from mgold/char-compare

Fix Char comparisons
Get rid of dependency on uniplate so AST does not need to derive Data or Typeable

This is motivated by wanting to add things to the AST that cannot
derive Data or Typeable
Fix bug in parser

34913d5 broke the parser in the following case:

f = '\"'

This commit fixes that.
Add note about how to request features to the main repo
Merge pull request #408 from timthelion/parserQuoteFix

Fix bug in parser
Add deriving as a reserved word
Change semantics of keepWhen/dropWhen.

They no longer propagate the right Signal when the left Signal
changes.